Best way is to destroy scams. Having scammy exchanges, scammy people running away, this is what make the trust to do not come. Little by little, by not funding them will make them disappear, and a trust will be contructed over the time.
Destroying scams is a very hard task, they are everywhere. What the government or us should do is to raise awareness. If we will raise awareness to the people and to the government about those technique of scams then it will be possible that the government will accept bitcoin and will accept the fact that bitcoin is good for the economy.
Once government finds a way to control or manipulate the bitcoin users surely they will let people know it for their people can earn and be benefited from it same with they can get taxes through the users once they find a way how to put taxes on each user.